Ultrafast Ultrasound Imaging of Ocular Anatomy and Blood Flow.
Ultrafast Ultrasound Imaging of Ocular Anatomy and Blood Flow.
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眼科解剖和血流的超声超声成像。
DOI：
10.1167/iovs.16-19538
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发表时间：
2016-07-01
影响因子：
4.4
通讯作者：
Silverman RH
中科院分区：
文献类型：
--
作者：
Urs R;Ketterling JA;Silverman RH
目前，眼科超声成像是使用机械扫描单元件探头进行的。这些探头总体功能有限并且缺乏血流成像的能力。线性阵列系统能够检测血流，但这些系统超出了眼科声强度安全准则。我们的目标是实施和评估一种新的基于线性阵列的技术，即复合相干平面波超声，它可以在安全的声强度水平下提供超快成像和血流描绘。我们比较了在传统聚焦模式和平面波模式下运行的 128 元件、18 MHz 线性阵列产生的声强度，并表征了信噪比 (SNR) 和横向分辨率。我们开发了平面波 B 模式、实时彩色流以及以 20,000 帧/秒的速率连续收集的后处理数据中的慢流高分辨率描绘。我们通过复合在 ±10° 范围内获取的平面波图像来获取眼睛后极的体内图像，并生成描绘眼眶和脉络膜血流的图像。当阵列按常规操作时，多普勒模式超出了美国食品和药物管理局的安全指南，但平面波模式完全符合指南。平面波数据可以生成高质量的复合 B 模式图像，并且信噪比随着复合帧数量的增加而增加。实时彩色血流多普勒可轻松可视化眼眶血流。对持续采集的 1.6 秒数据块进行后处理，可以高分辨率描绘心动周期内的眼眶和脉络膜血流。新开发的高频线性阵列与平面波技术相结合，为评估眼部解剖结构和血流以及其他瞬态现象（例如心动周期中的血管壁运动和眼跳引起的玻璃体运动）的可视化和分析提供了机会。
Ophthalmic ultrasound imaging is currently performed with mechanically scanned single-element probes. These probes have limited capabilities overall and lack the ability to image blood flow. Linear-array systems are able to detect blood flow, but these systems exceed ophthalmic acoustic intensity safety guidelines. Our aim was to implement and evaluate a new linear-array–based technology, compound coherent plane-wave ultrasound, which offers ultrafast imaging and depiction of blood flow at safe acoustic intensity levels. We compared acoustic intensity generated by a 128-element, 18-MHz linear array operated in conventionally focused and plane-wave modes and characterized signal-to-noise ratio (SNR) and lateral resolution. We developed plane-wave B-mode, real-time color-flow, and high-resolution depiction of slow flow in postprocessed data collected continuously at a rate of 20,000 frames/s. We acquired in vivo images of the posterior pole of the eye by compounding plane-wave images acquired over ±10° and produced images depicting orbital and choroidal blood flow. With the array operated conventionally, Doppler modes exceeded Food and Drug Administration safety guidelines, but plane-wave modalities were well within guidelines. Plane-wave data allowed generation of high-quality compound B-mode images, with SNR increasing with the number of compounded frames. Real-time color-flow Doppler readily visualized orbital blood flow. Postprocessing of continuously acquired data blocks of 1.6-second duration allowed high-resolution depiction of orbital and choroidal flow over the cardiac cycle. Newly developed high-frequency linear arrays in combination with plane-wave techniques present opportunities for the evaluation of ocular anatomy and blood flow, as well as visualization and analysis of other transient phenomena such as vessel wall motion over the cardiac cycle and saccade-induced vitreous motion.